The invention relates to a switchable support element for a valve train of an internal combustion engine, with a housing that can be installed in a receptacle of a cylinder head of the internal combustion engine and in whose bore hole there is an axially moving inner element that receives a force applied by a spring element pushing this inner element outward from the housing, wherein at least one coupling slide runs in a radial bore hole of the inner element, wherein this coupling slide can be brought into engagement in an axially extended position with a driving surface of the housing, wherein the extended position is limited by a height stop and wherein a projection extends past an outer casing of the housing for forming an outer anti-rotation lock.
The closest prior art is considered to be DE 10 2008 048 926 A1. There is a multifunctional clip in the outer casing of the housing. This clip extends past the previously mentioned outer casing with a sickle-shaped partial area for forming the outer anti-rotation lock. The anti-rotation lock is necessary to create a directed feeding of hydraulic medium to the support element and/or to align the radial bore hole of the support element with the coupling piston with respect to the surrounding construction.
At the same time, a height stop is realized by the clip mentioned above [that guarantees coupling play] through contact on an annular shoulder of the inner element and an inner anti-rotation lock.
The clip is broken off in the event of operation with enormous loads. In addition, someone skilled in the art knows that the already thin-wall inner element is weakened due to the formation of the inner anti-rotation lock (longitudinal flattened sections) and also loses guide and sealing length. A simple adjustment of the axially extended position of the inner element [coupling play] is also not possible, because the clip must be disassembled again after fixing an actual play.
In addition, switchable support elements are previously known whose outer anti-rotation lock is realized by means of a pin sitting in a window of the housing. Under some circumstances, the pin can become loose during operation. In addition, the housing can become deformed during its assembly.
Therefore, a switchable support element must be created in which the disadvantages mentioned above are not observed.